Method of sealing ampoules



March 15, 1949. F. D. PALMER 4 $4 METHOD OFSEALING AMPOULES Filed Oct.22, 1943 Patented Mar. 15, 1949 UNITED STATESEPATENT OFFICE METHOD OF-SEALINGVAMPOULES Frank D. Palmer, Chicago,"Ill., assignor to'Z'FJD.

.Palmer, Inc., 'Chicago, 111.,

Illinois a corporation "of Application October 22, 1943,..SerialNo."50'1',269

'ipeutics, etc., with one end open, theother end having been closed inthe processof producing .the ampule.

It has long been the practiceby therapeutic "manufacturers tofillampules, of the above'mentioned type, with the desired quantity ofpowder or liquid and to eifeotclosing-and sealing of the open end of theampule by manual labor. Inthe manual operation, a portion ofthe.-ampule;-above :the level of the material therein, is suchjportionis softened whereupon the open end portion of the ampule is pulled awayfrom the lower portion in such a Way that the diameter of the heatedportion contracts and effectsthe clos- 'ing of the ampule. :usuallybrought about by rotating or twisting one part of the ampule while theother part is held "against rotation andpulled-longitudinally from therotated part. To facilitate, this operation and to reduce the timerequiredto heat theampule to .the required fusing temperature of the,glass, the most commonly used ampules have been initially provided withan elongated, reduced-diameter mouth portion. The reduced diameter mouthportion has usually been formedby heating the ampule and pulling'onepart away; from the other much as inthe process of sealing filledampules as above described.

.The sealing :of ampules in the -.oonvention'al rmanner above referredto'and the-production of reduced mouthportions in a corresponding.manner, frequently,.if;notalways, results in thefor- :mation on theampuleof an extrathin walled por- .tlon which ismuch more subjecttobreakage than the other, normal thickness portions thereof.

Within recent years, certain'machines have been developed forfilling and'closingampules but they -'-effect'.the closing "and sealingsubstantially :by :mechanically oarryingoutithesame steps as were.eiiectedin the manual gclosingy-and sealing of heated until Thecontracting and closing is et-ii .aampule inthe-groove f2 ampules asalreadyreferred to hence, the objec; tional thinned wall, portions are.often, if not. always, present in the mechanically sealed ampules aswell as in manuallylseale'd ampules.

The main .object .of thepresent invention is to provide an improvedmethod ofclosing and sealing an ampule soas to avoid anymaterialreduction of the thickness of any part of the closed and sealed ampule;'toprovidelsuch a method which -.may be practicably effected bymechanical means which will operate at alhigh rate of speed; to providean improved ..ampule closing and sealing method which. wilLfacilitatethe closing and sealing operations byieliminatingthe,production ofvapors in the ampulebyreason ofheat transmitted through the walls of theampule to any. liquid preparation delivered .into the ampule; and in.general it is theobject .of the invention to provide an improved ampuleclosing, and sealing method.

Other objectsandadvantages of the invention .will be understoodsby.reference to the following specification and. accompanying drawingwherein there is moreorless diagrammatically illustrated a-selectedembodiment of the invention and cer- 1 tain modifications-thereof.

In the-drawings:

Figs. 1 to 6, inclusive, are .diagrammaticillustrations of thesuccessive. steps of the improved method;

Figs. '7 -and8. are fragmentary plan sections on thevlines '|-'l andspectively;

Fig..9 illustrates .-the .beginning of a modified method;

Fig. 10 is a fragmentary illustration correspond- ..ing-to a portion ofFigsshowing amodified-arrangement; I and .Fig. 11 is a.furthermodification of the closing .step represented in. Fig.5.

A typical glassampule inthe. form in whichlit is received by thetherapeutic manufacturer from the. ampulemanufacturer.isshown in Fig. 1.It .consists of an elongated cylindrical side wall I 2 and a bottom wall[3.

The ampule isusuallyprovided intermediate its cnds'witha slightlyreduced circumferentially ex ttending portion 1 4 which servestofacilitate opening of the ampule after it is closed. Opening isusually effected :by drawing a file across the formed by the reducedpor- 8-8 of Figs. 2 and 5, re-

tion l4 so as to scratch the glass whereupon the ampule may be readilybroken transversely in the zone of the groove M.

The ampule is preferably rotated during the heating and other stepshereinafter described, there being provided any suitable means foreffecting such rotation while holding the ampule temporarily in a fixedposition or station and during the movement of the ampule to successivestations.

According to the presently preferred embodiment of the improved method,a straight walled ampule is initially heated in a circumferential zoneindicated at I5 by means of fiames from suitable gas burners I6. Theinitial heating of the zone l5 of the ample as shown in Fig. 1 iscarried on to such an extent that the glass in the circumferentiallyextending heated zone is softened. The ample may be advanced by means ofa conveyor or other suitable means from the initial heating station to asecond station or position wherein a pair of forming fingers or swagingbars I1, I! approach the softened zone of the ampule and press itinwardly to form an inwardly offset bead or slightly reduced neckportion l8.

The fingers l1, l1 preferably have the ends thereof, which engage theampule wall, smoothly rounded as indicated at I 8. They may be providedwith arcuate portions 9, as best shown in Figs. 2 and 7, of a radiuscorresponding to the radius of the outside of the initially formed neckportion l8. The swaging operation of the fingers I1 is executed whilethe ampule continues to be subjected to heating flame directed into thezone of the ampule in which the neck I8 is formed. Suitable gas burnersare provided for delivering the desired heating flame against theampule, preferably immediately below the swaging fingers l7, I! whichare also incidentally heated so as to avoid any material chilling efiecton the engaged portion of the ampule.

In a succeeding step in the method, the neck l8 may be further reducedby means of swaging members 2|, 2| which are, in general, similar to thefingers H, I! except that the opening provided between the arcuateportions thereof is smaller to such an extent that a greatly reducedneck 22 will be formed in the ampule. The heating of the ampule in thelast mentioned neck reducing station may be effected by means of gasburners 23, 23 which also preferably direct suitable flames into theneck zone immediately below the swaging members 2|, 2|.

It will be apparent that instead of forming the neck 22 in only twosteps as illustrated, it may be effected in a larger number of stepseach of which increases the constriction only a small amount until ithas been reduced to the desired size substantially as represented inFig. 3.

In some instances, the ampule may be filled immediately after completionof the formation of the neck 22 and the filling may possibly be executedwhile the ampule remains in the posi tion in which the final neckforming operation is performed. However, it appears preferable that thefilling be executed in a different station to which the ampule may beautomatically advanced after the neck 22 is completed. Preferably, asufficient time interval is caused to elapse between the final neckforming step and the filling of the ampule to permit the ampule to coolso as to avoid any tendency to vaporize any liquid or other materialintroduced into the ampule. The cooling may be artificially hastened, orit may be controlled so as to insure annealing of the glass so as toprepare it for additional heating and flexing operations which willpresently be described. If desired, the ampule, after formation of theneck 22, may be passed through a suitable oven for annealing purposes.

A filling station is represented in Fig. 4 and the filling is preferablyaccomplished by inserting an elongated small diameter spout or needle 24through the neck 22 and to the bottom of the ampule as illustrated. Therequired quantity of powder or liquid is delivered through the needle tothe ampule after which the needle is withdrawn. The filled ampule isthen preferably advanced to still another station where the closing andsealing operation may be eifected or at least initiated.

A closing and sealing station is represented in Fig. 5 wherein a pair ofsealing fingers or shears 25, 25 are illustrated as having sheared offthe upper end portion of the ampule, the separation having been effectedin the zone of the smallest diameter of the neck 22. The neck will havebeen further heated, to fusing temperature, by flames delivered by gasburners indicated at 26, 26.

The shear members 25, 25 cooperate with each other to completely closethe neck 22, the innermost surface portions of the neck 22 being broughtinto engagement with each other and caused to fuse together to form asealed end 21 on the ampule. The cut off end portion 28 may be caught ina suitable tray or chute associated with the sealing station representedin Fig. 5 and disposed of in any desired manner. Rotation of the ampoleis preferably continued during the cut off and sealing operation and theend wall 2'! of the ampule will, of course, be acted upon by theengaging lower surface of the lowermost shear finger 25. As shown inFig. 5, the shearing end of the lowermost fingers is preferably beveledas at 29. Such beveled surface and the adjacent undersurface of thefingers will tend to flatten down sealed end wall 21.

The sealing operation represented in Fig. 5 may be carried onimmediately after the filling operation represented in Fig. 4, and ifpreferred, the neck 22 may first be subjected to a further constrictionoperation such as represented in Fig. 3 to thereby reduce the workrequired of the shearing fingers 25, 25. The shearing fingers may beformed with sharpened notched ends as shown at 30, 30 in Fig. 8, thenotches serving to embrace the reduced neck 22 of the ampule and toinsure uniform inward constriction of the neck as an incident to aclosing movement of the shear members and the rotation of the ampule.

After completion of the shearing operation represented in Fig. 5 thenewly formed end closure of the ampule may be subjected to a finishingstep in which a suitably formed pressure block 3| is brought to bearagainst the end of the ampule while the latter is maintained inrotation. This block may bemade of wood such as ash and it may bemaintained water wet to prevent burning thereof. It will be apparentthat rotation of the ampule against the pressure block 3| will result ina uniformly flattened or other shaped end wall as may be desired.

In some instances it may be preferred to avoid any end shaping effect ofthe shears 25, 25 as illustrated in Fig. 5. In such an instance thearrangement shown in Fig. 10 may be employed wherein the shear fingersare represented at 32 and 33.

"Emil-es The-lo'wershear fingers '32--;-in-that case-hasits sharpenedend so beveledor-hollow-groundless indicated at34-that its archedorinclined-surface will substantially conform to'the convex shapeof theend of the ampule which would normally'-result from the closing oftherieck' 22 byea fuither step such as represented'in Fig. 3. A" furthermethod by which the endxshapingw function of the shears shown in Fig.may be eliminated is to employ cooperating shear-fingers acting in thesame plane and havingcooperating endswhich are moved into end toend-engagement "with each other. Such an arrangement is-typified in themodification illustrated in Fig. 11.

In the described method of closing and sealing the ampule, the liquid orother material delivered into the ampule in the step represented in Fig.4 is not subjected to heating during the preceding steps represented inFigs. 1, 2, and 3. For that reason and because of the cooling of theampule before filling, there will be but little or no vapor formed inthe ampule when it is filled in the step or station represented in Fig.4.

In some circumstances, it is preferred to fill the ampule before theheating and closing steps are started. In such a case the ampule may beinitially filled as represented in Fig. 9 and the initial heating stepeffected by the burners I6 while the ampule is rotated with its contenttherein. The neck forming steps represented in Figs. 2 and 3 may becarried on in successive operations. Before the final sealing steprepresented in Fig. 5 is begun, it may be advantageous to provide forthe passage of a sufficient time interval to permit cooling of theampule and its content and the escape and/or condensation of any vaporswhich may have been formed within the ampule as an incident to theheating during the various steps through which the ampule passes asalready described. Such time interval may be provided in an automaticmachine by suitably spacing the positions of the last neck formingoperations and the severing and sealing operation, or by any otherarrangement for delaying the delivery of a filled ampule from the finalneck forming station to the neck closing station. The required timeinterval may be lessened or completely eliminated by forcibly evacuatingor dispelling the vapor-s by the use of vacuum or compressed air meansand by naturally or artificially cooling the ampule, for example, bymeans of a cool air current. It will, of course, be understood thatelimination of vapor, before sealing the ampules, is advisable because,unless such elimination is efiected, the heating of the ampule in thefinal closing and severing steps may sometimes raise the temperature ofthe ampule to such an extent that any trapped vapors would expand to thepoint of bursting the ampule.

The formation of the restricted neck portion as a preliminary to thefinal severing and sealing operation permits the final severing andsealing operation to be performed with the application of a minimumamount of heat which will not be sufficient to vaporize any liquidcontent normally enclosed in ampules of the character described. or inany event, said minimum amount of heat required will be insuificient tovaporize enough of the ampule content to develop pressure enough withinthe ampule to burst or prevent closing of the ampule.

As shown in Figs. 2 and 3, the constricting fingers I1 and 2i aredisposed at a downwardly.

6 inclined angle. These fingers are preferably moved longitudinallyinwardly in a downwardly inclined plane such as the plane in which theyare represented, sothat they tend to bend or fold the side wall portion35 inwardly and downwardly without any material *stretching and thinningeifect on any part of the finished or closed ampule. The inward anddownward folding of the portions 35 is, of course, accompanied by someshortening of the overall length of the ampule. The upper inwardlypressed wall portions represented at 38 may possibly bestretched andthinned somewhat butsince the upper portion of the ampule containing thewall portions 36 is removed, there is no disadvantage in that thinning.It is, however, of substantial value that the end closure formingportion 35 of the ampule is maintained at substantially its normalthickness. The severing operation represented in Fig. 5 similarly avoidsany stretching and thinning efiect since the severing fingers 25, 25produce only a very small amount of inward movement of the neck portion22 of the ampule while at the same time producing some further downwardfolding of the portion 35.

In prior ampule filling and sealing methods,

tapered and reduced mouth end ampules have usually been employed. Suchampules have been used because the lesser amount of heat required hadthe more or less effective tendency of avoiding vapor pressure burstingof the ampules. Such tapered ampules, although being the only onesheretofore considered practicable because of the limited heatingrequired for the sealing operation are, however, objectionable becauseof their inherent weakness due to the thinning of the glass wall in thetapered mouth portion.

The herein described method makes it entirely practicable to employ themuch more desirable straight walled and stronger ampules which, inaddition to their advantage of strength, are adaptable to more compactand less expensive packaging. Also, the described improved method issuch that it may easily be practiced by means of high speed, automaticmechanism.

Modifications, in addition to those mentioned herein, may be made in thedescribed method without departing from the invention as set forth inthe following claim.

I claim:

The method of producing a filled, closed ampule from a conventionalstraight-walled ampule, which comprises the steps of heating acircumferential part of the ampule above the normal level of the contentof the ampule and, when such part is sufficiently heated, forming areduced neck in the ampule above said content level by applying to saidpart pressure directed inwardly and toward the bottom of the ampule soas to avoid stretching and incidental reduction of the thickness of theneck portion which will ultimately close the ampule, the entire ampulebeing thereby warmed and some of the content of the ampule, whetherintroduced thereinto before or after formation of said neck, subjectedto vaporization, permitting the escape from or condensation in theampule of vapor which may be present therein and then reheating saidreduced neck portion to fusing temperature and severing the ampuletransversely at said neck so as to close the neck and effect fusion ofthe meeting surfaces thereof, whereby the closing ,is effected withouttransmitting sufficient heat to the ampule content to cause theproduction of 7 sumcient vapor in the ampule to hinder the closing ofthe ampule as aforesaid.

FRANK D. PALMER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number 10 Number Name Date Brumley Feb. 6, 1934Zimber July 24, 1934 'Loepsinger Jan. 7, 1941 Cozzoli Oct. 7, 1941 DeNeumann Dec. 9, 1941 Cozzoli June 26, 1945 FOREIGN PATENTS Country DateAustralia, Sept. 2, 1943 Great Britain Sept. 23, 1936 Germany Dec. 16,1937

